<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>17_margin合并问题</title>
    <style>
        .box {
            width: 200px;
            height: 200px;
        }
        .box1 {
            background-color: deepskyblue;
            /* margin-bottom: 110px; */
        }
        .box2 {
            background-color: orange;
            margin-top: 110px;
        }
        .test {
            width: 200px;
            height: 200px;
            display: inline-block;
        }
        .testa {
            background-color: purple;
            margin-right: 50px;
        }
        .testb {
            background-color: tomato;
            margin-left: 50px;
        }
    </style>
</head>
<body>
    <div class="box box1">1</div>
    <div class="box box2">2</div>
    <hr>
    <div class="test testa">a</div><div class="test testb">b</div>
</body>
</html>